# coding:utf-8
var1 = "hello world!"
var2 = "python"
print(var1[0])
print(var1[1:5])
print(var1[:6] + var2)
print(var2 * 2)
print("y" in var2)
print("a" not in var2)
print("\n", r"\n", R"\N")  # r R打印原始字符串，没有转义

